Field of Invention
The present invention relates generally to round balers, and more specifically, to round balers with rotational baling chambers.
Description of Related Art
Conventional round balers receive crop material and form the crop material into compacted bales in a baling chamber. There are generally three major cycles in the operation of a round baler: a bale-forming cycle, a bale-wrapping cycle, and a bale-ejecting cycle. The baling chamber is typically run at a constant rotational speed throughout its bale-forming and bale-wrapping cycles.
An important part of operating a round baler is controlling the feed rate of material into the bale chamber. If too much material is fed to the bale chamber it can plug the baler, whereas if too little material is fed then the bale will deteriorate in the chamber. In a conventional round baler pulled with a tractor, controlling the feed rate is accomplished by varying the tractor's ground speed and engine speed. In a continuous round baler with an open accumulation area, there are several reasons why this method is inadequate. First, in order to minimize the cycle time and thus the amount of accumulated material, it is desirable to increase the bale chamber speed to reduce the bale wrapping time. In addition, if the baler is towed behind a combine for collecting residue, the ground speed will be determined by the optimum combine speed for the grain harvest, and the material infeed rate to the baler cannot be changed this way. Furthermore, in a conventional round baler, tractor engine speed is varied to adjust the Power Take Off shaft (PTO) speed and thus the drive speed of the baler. If the baler is pulled by a combine, the engine will be run at full throttle for grain harvesting reasons, so the baler speed cannot be sufficiently adjusted by changing engine speed. In addition, the optimum baler speed may be significantly higher when feeding accumulated material into the baler than when feeding new (unaccumulated) material.
U.S. Patent Publication No. US 2011-0023732 A1, assigned to the assignee of the present invention, discloses a variable speed baler configured to vary the speed of a baling mechanism in accordance with the operational cycles of the baler. While such arrangements are useful there is room for improvement.